Automatic air valve



June 17, 1952 J. H. WHITE ET AL v 2,601,216

AUTOMATIC AIR VALVE Filed Deo. 18, 1948 WsL/W Patented June 17, 1952 AUTOMATIC AIR VALVE John H. White, Old Greenwich, Conn., and Rudolph T.v Schoerner, Oaklawn, R. I., assgnors vto Taco Heaters, Incorporated, Providence, R. I., a corporation of New York Application December 18, 1948, Serial No. 66,094

8 Claims.

This invention relates to an automatically operating air vent valve allowing the passage of air therethrough and preventing the passage of water or similar liquid, said valve being especially adaptable for use in a heating system, pumping system, or similar application wherein it is necessary to vent air or gas from a space and prevent the escape of water or similar liquid.

In heating system radiators, as an example, it is well known that it is necessary to vent the air or other gases produced in the system therefrom so that the heating fluid in the radiator will completely ll the radiator. This will give maximum heat transmission between the heating uid, such as water, and the walls of the radiator. The water frequently contains dissolved air, or air can leak into the system in various manners and collect at the top of the radiators. Previously, manually operated valve arrangements have been employed for the purpose of venting the air from the radiators requiring each radiator to have its valve individually opened. There is seldom any systematic opening of the valves so that frequently air will be entrapped in the radiators and will remain for considerable periods f time before venting which will result in an inefficient operation of the system. Also, immediately after the radiators have been vented manually, it is possible that air will again become trapped in the radiator because of some unusual occurrence in the heating system. A considerable period may elapse before the radiators are again vented to l remove the trapped air. i

Various automatic valves have been suggested, but these all have defects, one of the mostimportant defect being the undesired escape of water from the radiator which may damage the floor or surroundingvobjects. Some of the valves require critical adjustments in assembly and in operation.

One of the principal objects of the present invention is to provide an automatic vent valve which will vent air from a heating, pumping, or similar system, but which will prevent the passage of water or other similar liquid therefrom. In one aspect of the invention, a porous rigid body or similar means is employed to pass air and to control and to restrict the rate of flow of water from the system to a librous body located between the porous body and the outlet of the valve, said-fibrous body normally being pervious to air but substantially impervious to water upon becoming wet, impervious meaning substantially impervious. The combination of the porous plug means with the .fibrous body to bloot'. the dow The brous body preferably should be made of lbers capable upon wetting with water or the like, of swelling a major amount when unconned. The swelling should be reasonably rapid so that when the fibrous body is confronted with water at the rate permitted by the porous rigid body, it is capable of swelling to close the passage between the porous rigid body 4and the atmosphere with sufficient rapidity to avoid leakage of water beyond the valve.

In a further aspect of the invention, a ber can be employed, such as one of cellulose ber normally used `in the manufacture of paper or piper board and which has not been subsequently treated so as to reduce the swelling characteristics, such as by vulcanizing, such a fiber being termed herein an untreated cellulose fiber. A kraft process ber is one example of such a ber having unreduced swelling characteristics. Said body and fibers preferably are chosen to have at least a predetermined real volume in relation to the active or actual space occupied by the body and to have a predetermined swell rate when unconfined. With this aspect of the invention, any suitable type of ow restriction control means to the brous body can be employed, the initial swell rate of the fibers being such as to block the flow of water which might be passed by the control means. Swell rate can be defined as the percentage increase in thickness of the normally dry fibrous body per specified unit of time.

It isv desirable that choice of brous body should be made on the basis so that when swelling of the bers -composing the brous body occurs under unrestrained conditions, the swelling more than causes the body to ll the cavity within which it is coni-ined when restrained. v

As a further feature, the rigid porous plug, or control means having intercommunicating pores, can be employed in conjunction with any suitable means to block a ow of water from the porous plug, said control means permitting the passage of air.

The aforementioned brous body when relatively dry may have intercommunicating pores therethrough which will be squeezed shut when the fibrous body absorbs water and the body is coniined between the walls of a cavity or restraining structure. The iibrous body is used to control an outlet passage leading from the porous plug or other control means, the porous plug being located in an inlet passage of the vent valve. The size of the pores in the plug are selected so as to inhibit the free flow of Water and to pass water at such a rate that the fibrous body will swell to close olf the pores through the fibrous body. The pores are closed olf before water can leal; through the'body-to the-outside of the vent Valve.

When the fibrous body is restrained, the body will absorb only enough water to create a pressure sufficient to prevent a further passage of water. Thus, within certain limits, the valve will function independentv of pressure` in the radiator or system tobe Vented;

After the fibrous body haslbecome impervious to the now of Water, there may be some evaporation from the outer portions, butthis will be replenished by water passing through the porous plug at a controlled rate until air collects-under, the porous plug, shutting off this source of replenishment, thereafter evaporationwill continue z until the fibrous` body becomes pervious tov air.

In a preferred form, the fibrous body fibersare in layers parallell to eachother with a substantially random orientationv of the fibers in said layers. transverse to the passage. of the water from the porous plug to the outlet passageway.

As mentioned previously, it has. been found that the actual or real volume of the fibers themselves preferably should bear a predetermined relationship to the active or actual volume of the space occupied by the fibrous body for proper functioning of the brouselement in closing olf the egress of water from the valve. Because of this relationship and because of the control of the flow of water through the porous plug, there is no critical adjustment required of the conning cap for the fibrous body; or pressure exerted by the cap onthe fibrous body, the cap merely being screwed' into place to a positiondetermined by the structure of the valve body. Also, there is no critical adjustment ofl the controlmember regulating the flow to the; fibrous body.

The porous plug can take various forms. When the correct fibrous` body is employed, a single or a plurality of restricted passages can be used, the passages being chosen to control the flow of water at the proper rate to the fibrous body. The porous plug does not necessarily have to be an element separate from the valve body but can be integral therewith.

This application is ay continuation-in-part of copending application, Serial No. 732,456, filed March 5, 1947, and now abandoned.

One of the principal advantages of the invention is that the valve will operate to vent air from a radiator and yet prevent the passage of water in such a manner as toV disadvantageously leak on the floor or elsewhere. Also, the valve combination canbe manufactured and assembled economically and with ease; there being no critical adjustments necessary.

These and other objects, advantages, and featuresof the invention will become apparent, from the following description and drawings which are 1' merely exemplary,

In the drawings:

Figure 1 is a sectional view of a valve showing one form of the invention.

Figure 2 is a view taken in the direction 2-2 of Figure 1.

Figure 3 is a sectional view of a modified form of the invention.

In a valve made in accordance with the present invention, valve body I0 (Fig. 1) may be made The fibers arearranged substantially i..

of metal or suitable material, said body having an inlet passageway II and a chamber I2, said chamber having a shoulder I3 supporting a rigid porous plug I4 in said chamber. Inlet passageway II is in communication with one side of the chamber I2, serving to, connect oneface of the porous plug with the interiorofl thef radiator or other space. The chamber I2 does not necessarily have to be distinct entity, the term chamber being used to designate the area or space in which the porous plug, porous material, or other control means is located. Outlet passageways `I maybe provided leading from the cavity I6, saldi cavity being in communication with the outletside-ofthe chamber I2 and located between the porous plug and the outlet passageways I5, said cavity serving-as part of the outlet passage fromthe porous control plug. A cap I'I is screwthreadedly engaged at I8 with the body I0 of the valve..

Fibrous body lislocated; inthe. cavity I6, cap I1 serving` as; part ofi thev confining or.. restraining means. therefor.. Itis thus seen that.4 the fibrous body |19; is located between the chamber I,2 and porous plug thereinand. outlet. passaeeways I5. The fibrous body willbe described in detailliert?- after. If desiredla vent hole 20Y can be located in the cap II'.

A manually operable valve 2I may be. screwthreadedly engaged. in the valve body I0` for the purpose ofv permitting thevent valve to be operated manually.

The porous plug I4 can be made ofvarious materials such as,- for example, porous graphite, porous bronze, or a suitable porous ceramic. The materials are selectedv so as to haveI the desired porosity and'preferential'air and water flow characteristics. By this is meant that' they pass air readily' but; restrict orinhibit the flow of water. A. porousbronze plugis preferred', such a plug being' formed by conventional powder metallurgy techniques. The size of powder, shaping thereof, and sintering, preferably without coining, being adjustedtoA produce the desiredv preferential control results. MerelyV by way of example, a porous bronze, plug which has been found to be satisfactoryvwill' at apressure of5 Sopounds per square inch, pass about 2Y cubic centimeters of water per minuteandy about 275 cubic centimeters of air per minute. The same plug at 5 pounds per square inch pressure will pass about .58 cubic centimeters of water per minute and about 40 cubic centimeters of air per minute. The density of such a plug; could' be about 6.2. These characteristicsy will' varyA considerably-, and will depend upon the type of service and manyotherfactors. As previously mentioned, the plug may be in an integral part of the valve body or may be located in the straight wall portion of the inlet passageway.

The fibrous body in cavity I6 preferably is made from a kraft process, ber, although other similar fibers can be used. In one type of satisfactory fibrous body, the ber is medium well cooked and beaten, and the board made on a wet machine. The fibers preferably are arranged in parallel layers, said layers preferably having the bers randomly oriented in each layer. Fibrous bodies found to be satisfactory may have apparent densities of from 0.80 to 1.40, and, an initial swell rate for the rst minute of more than 20% when exposed to water and when the body is unrestrained. As one example of a suitable fiber, the initial swell rate is 20% for the first minute. The same fiber will' swell 70% in five minutes. This ber is a kraft process fiber made as indicated. The swell rate is not necessarily a straight line relationship but should be rapid or quick the first minute. The particular swell rate also is related to the real volume of the fibers. The fibrous body may be made up of a plurality of wafers or washers suitably shaped to fit within cavity I6. The brous body extends across the passageway from the porous plug I4 to the outlet passageways l 5 and preferably is arranged so that it is slightly larger than the plug l 4 or so that the edges thereof will rest on the shoulders of body I0.

Preferably, the fibers are arranged so as to lie transversely across the passageway from the plug to the outside of the valve as distinguished from lengthwise across the passageway or parallel to the fiow.

In the invention shown herein, the fibrous body after once becoming wet extends between two of the faces in which it is located, one face of which may be defined by the upper part of the porous plug. When first placed in the cavity, it is not entirely essential that the body completely fills the same, but after once becoming wet, the fibrous body extends between opposite faces thereof. When there is no water in contact with the fibrous body and after it has had time to dry, at least partially, the fibrous body becomes pervious to air. This is apparently due to the creation of interstices between the various fibers by the shrinkage. This permits the passage of air or gas from the inlet passageway through the porous plug and through the fibrous body to the outlet passageways of the valve. When water fiows through the porous plug at a controlled rate, the fibers in the fibrous body will swell to close the interstices and cause the body to become impervious to the passage of water before water can flow through so as to flow onto the floor or surrounding objects. When a plurality of wafers are used, the air may pass out between the wafers as well as through them. If the peripheral edge of the fibrous body does not extend beyond the porous plug when first placed in the valve, it

should be chosen so that after first swelling radially, it will extend beyond the periphery of the porous plug.

The porous plug in chamber l2 is one that controls the rate and limits the flow of water therethrough to that rate at which the fibrous body can become impervious to the flow of water to prevent the escape of water from the valve in a damaging manner. It can be theorized that as the fibers of the fibrous body absorb water, expansion of the fibers in the fibrous body and because of their constraint in the cavity, will cause force to be exerted in such a manner as to set up sufiicient internal pressure to counteract the pressure of the liquid tending to pass through the fibrous body. Theoretically, the fibrous body will absorb only enough water to create a sufficient pressure to prevent further passage of water therein. It is thus evident that within practical limits, the valve will shut off regardless of the pressure existing in the radiator. Normally, the pressure in a heating system does not exceed 30 pounds per square inch and seldom will it be above 60 pounds per square in-ch. After the fibrous body has absorbed sufficient water so as to close oli the passage of water therethrough under the existant pressure, water may evaporate from the surfaces thereof, but this will be replaced by water flowing at a controlled rate through the porous plug so as to cause the 6 fibrous body to cut off the passageway between the porous plug and the outlet opening l5. If a minute quantity of water should possibly pass through the outlet I5, it will evaporate directly from the cap or body because of the accurate control by the combination present in the valve.

An alternate and preferred form of the invention is seen in Figure 3 wherein valve body 22 has an inlet passage 23 with a manual control valve 24 therein. The chamber portion 25 has a porous plug 26 similar to that described in Figure l. A filter 21 may be placed at the inlet side of the porous plug 26 so as to prevent the porous plug from becoming clogged. Said lter, for example, may be a piece of hard filter paper. The cavity 28 has outlet passageways 29 opening therefrom, there being any desired number of said passageways 29 opening around the periphery of the valve body. There must be sufficient vent area to permit evaporation of water from the fibrous body so that it will pass air. Cap 30 is screw-threadedly engaged at the top of the Valve body, said cap having a shoulder 33 abutting body 22, it not being necessary to provide an adjustment of said cap relative to the brous body elements. Fibrous body 3 I is located in cavity 28, said fibrous body having central aperture 32 therethrough if desired, and with its peripheral edge resting on shoulder 34. It has been found that this shoulder should be at least Ile" for a 1/2" diameter fibrous body. The fibrous body may be comprised of a plurality of discs similar to those described in Figure 1, seven discs being used in one form of the invention.

As previously mentioned, it has been found that the real volume of the fibers of the fibrous body preferably should occupy a certain predetermined volume of the active space in which the fibrous body is restrained. The term active space means the actual space occupied by the fibrous body after it once has been wet. If the real volume of the fibers is at least 50% of the volume of the active space, the fibrous body will satisfactorily close off the controlled flow of water thereto, particularly when the fibers have the desired characteristics as mentioned hereafter'. The fibrous body should have at least two opposite walls constraining the same so that upon absorption of moisture, sufficient pressure will be exerted to make the fibrous body impervious to further fiow of water therethrough. The fibrous body also preferably should be an untreated cellulose fiber as previously explained and should have an initial swell rate of at least 20% for the first minute. The swell rate desired will be governed to some extent by the characteristics of the porous plug.

As an example of a satisfactory arrangement of a fibrous body for use with a porous plug which at 30 pounds per square inch will pass about 2 cubic centimeters of water per minute and 275 cubic centimeters of air, a plurality of discs of a kraft process fiber board can be used. The fibers are an untreated cellulose and are randomly oriented in substantially parallel layers in the board. The real volume of the fibrous body is made at least 50% of the active space and preferably about and the initial swell rate, 20% in the first minute.

The vent valve of the invention can be used in different places where it is desired to vent gas from a space and yet prevent the escape of liquid therefrom. Various modifications can be made in the details of construction described herein 7i withoutdeparting from-the spirit of the invention exceptasdenedinthe appended claims.

What is claimed is:

l. A-n automatic airvent valve for a radiator or the like, comprising a valve body, an inlet passageway in-,saidbody, anoutlet passageway having a cavity therein, saidcavity being connected to said inlet'passageway, a water absorbent fibrous body in saidcavity, saidfibrous body being normally pervious to air and becoming impervious to water upon absorption of, water, and a porous body in said` inlet passageway, said porous body having intercommunicatng pores therethrough passing air but restricting thepassage of water to a rate such that absorption of water by the fibrous body will take place at substantially the same rate asA said passage of water, and thus render said brous body impervious to water,v

whereby said-'valvewill pass air and retain water.

2; An automatic air vent valve for a radiator or the like, comprising a valve body, an inlet passageway in said body, an outlet passageway having a cavity therein, saidcavity being connected tovsaid'inlet passageway, awater absorbent brous body in said cavity, said brous body having fibers randomly oriented in substantially parallel planes, said'fibrousbody being normally pervious to air and becomingimpervious upon absorption of water, and a porous element in said inlet passageway, said element having intercommunicatng pores therethrough passing air but restricting the passage. of Water to a rate s uch that absorption of water by the fibrous body will take place at substantially the same rate as said passage of water, yand thus render said fibrous body impervious to water, whereby said valve will pass air and retain water.

3. An automatic air vent valve for a radiator or the like, comprising a Valve body, an inlet passageway in said body, an outlet passageway having a cavity therein with opposite walls, said cavity being connected to said inlet passageway, a water absorbent fibrous body extending between said opposite walls, said brous body being normally pervious to air and becoming impervious upon absorption of water, and a rigid plug in said inlet pasageway, said plug having intercommunicating pores therethrough passing air but restricting the passage of water to a rate such that absorption o f water by the brous body will take place at substantially the same rate as said passage of water, and thus render said fibrous body impervious to water, whereby said valve will pass air and retain water.

4. An automatic air vent valve for a radiator or the like comprising a valve body, an inlet passageway in said body, an outlet passageway having a restraining cavity therein, said restraining cavity being connected to said inlet passageway, a water absorbent brous body in said cavity, the real volume of the fibers of said nbrous body being at least 50% of the active volume of the fibrous body and having a swell rate of at least 20% for the first minute, said fibrous body being normally pervious to air and becoming impervious to air and water upon absorption of water, and a capillary water flow control element in said inlet passageway, said element restricting the flow of water therethrough to the rate at which it is absorbed by the brous body so as to substantially prevent the flow of water through said vent valve but allow the venting of air.

5. An automatic air vent valve for a radiator Q1.- 'ih lik@ GQmpIfvSing ay valve body, an inlet passageway in said body, an outlet passageway having a restraining cavity therein, said restraining cavity being connected to said inlet passageway, a water absorbent fibrous body in said cavity, the real volume of the bers of said fibrous body being at least about 50% of the active volume thereof and having a swell rate of at least 20% for the rst minute, the nbers being randomly oriented in approximately parallel layers, said fibrous body being normally pervious to air and becoming impervious to air and water upon absorption of water, and a capillary water iow control element in said inlet passageway, said element restricting the ow of water therethrough to the rate at which it is absorbed by, thev fibrous body so as to substantially prevent the flow of water through said vent valve but allow the venting of air.

6. An automatic air vent valve for a radiator or the like, comprising a valve body, an inlet passageway in said body, an outlet passageway having aV restraining cavity therein, said restraining cavity being connected to said inlet passageway, a water absorbent brous body in said cavity, the bers of said fibrous body having a real volume of at least 50% of the active volume thereof, said brous body being normally pervious to air andbecoming impervious to water upon absorption of water, and a porous rigid body in said inlet passageway, said brous body having intercommunicatng capillary pores therethrough preferentially passing air but restricting the passage of water to a rate such that absorptionof water by the fibrous body will take place at substantially the same rate as said passage of water, andA thus render said brous body impervious to water, whereby said valve will pass air and retain, water.

'7. An automatic air valve for a radiator or the like, comprising a valve body, an inlet passageway in said valve body, an outlet passageway having a cavity therein, said cavity being connected with said inlet passageway, a water absorbent fibrous body in said cavity, said body having fibers randomly oriented in substantially parallel planes, said fibers being located transverse of the path between said inlet and outlet passageways, said fibrous body being normally pervious to air and becoming impervious to water upon absorption of water, and a porous metallic element in said inlet, passageway, said element having intercommunicatng pores preferentially passing air and restricting the passage of water therethrough to the rate at which said brous body absorbs the same, said absorption rendering the brous body impervious to the passage of water, whereby said valve will pass air and retain water.

8. An automatic air valve for a radiator or the like, comprising a valve body having a nrst annular chamber therein and a second annular chamber of lesser diameter than said firstchamber connected to said nrst annular chamber and forming a shoulder therebetween, an outlet passageway connected to said rst annular chamber, an inlet connected to said second chamber, a water absorbent nbrous body in said first chamber, said brous body being normally pervious to air and becoming impervious upon absorption of water, the periphery of one face of said fibrous body resting on said shoulder, and a porous rigid plug lling said second chamber between said inlet passageway and said first chamber, said porous plug having intercommunicatng pores therethrough preferentially passing air but restricting the passage of water to a rate such that absorption of water by the fibrous body will take place at substantially the same rate as said passage of water, and thus render said fibrous body im pervious to Water, said brous body yextending after once wet between said rigid plug and an opposite Wall of said rst chamber.

JOHN H. WHITE.

RUDOLPH 'I'. SCHOERNER.

REFERENCES CITED The following references are of record in the le of this patent:

Number l0 UNITED STATES PATENTS Name Date Bradley Oct. 1, 1907 Bush Feb. 23, 1932 VGibson June 27, 1933 Scoppola Apr. 11, 1939 Zelnis Max'. 30, 1943 Simoneau Oct. 12, 1943 Mikeska Apr. 12, 1949 

